Abstract

Detailed phase diagrams are necessary for improving the temperaturestability of piezoelectricproperties of -based solid solutions. We report the phase diagrams of the (, Ba, Sr, Ca, and ) solid solutions over a broad temperature range of . It is found that the phase diagrams show several universal characteristics: (a) Curie temperature decreases sharply at low range; (b) the relation between and deviates from Vegard’s law; and (c) the tetragonal-orthorhombic phase transitiontemperature and the orthorhombic-rhombohedral phase transitiontemperature are almost independent of . We suggest that valence mismatch is the main reason for the rapid decrease in and the deviation of from Vegard’s law. It is also found that is mainly affected by the A-site cations, whereas and are mainly affected by the B-site cations.